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eHam Forums => Computers And Software => Topic started by: AG1LE on May 13, 2012, 10:29:38 PM



Title: FLDIGI: two new experimental features to improve CW detection and decoding
Post by: AG1LE on May 13, 2012, 10:29:38 PM
I have implemented two new experimental features to improve CW detection and decoding capabilities in FLDIGI softare.

1) Matched Filter  feature improves signal-to-noise making barely audible morse code detection  to work better in FLDIGI  CW mode.

2) Self Organized Map feature is using an artificial neural network algorithm from SOM http://en.wikipedia.org/wiki/Self-organizing_map (http://en.wikipedia.org/wiki/Self-organizing_map) to calculate best matching codebook entry from input vector using Euclidian distance method.

I have documented these experimental features in my blog as well as test results:

http://ag1le.blogspot.com/2012/05/fldigi-adding-matched-filter-feature-to.html (http://ag1le.blogspot.com/2012/05/fldigi-adding-matched-filter-feature-to.html)

I am looking for software developers who can compile this from FLDIGI tar ball, and don't need my support to get this running in their setup.

The software is alpha quality and not ready for broader distribution. If you have interest in testing/improving this software let me know. 


Title: RE: FLDIGI: two new experimental features to improve CW detection and decoding
Post by: AG1LE on May 20, 2012, 12:16:31 PM
I have implemented two new experimental features to improve CW detection and decoding capabilities in FLDIGI softare.

1) Matched Filter  feature improves signal-to-noise making barely audible morse code detection  to work better in FLDIGI  CW mode.

2) Self Organized Map feature is using an artificial neural network algorithm from SOM http://en.wikipedia.org/wiki/Self-organizing_map (http://en.wikipedia.org/wiki/Self-organizing_map) to calculate best matching codebook entry from input vector using Euclidian distance method.

I have documented these experimental features in my blog as well as test results:

http://ag1le.blogspot.com/2012/05/fldigi-adding-matched-filter-feature-to.html (http://ag1le.blogspot.com/2012/05/fldigi-adding-matched-filter-feature-to.html)


Thanks to Dave W1HKJ  and the FLDIGI community this project has moved forward quite a bit over the last week.  

I posted new promising test results in here:
http://ag1le.blogspot.com/2012/05/fldigi-matched-filter-and-som-decoder.html (http://ag1le.blogspot.com/2012/05/fldigi-matched-filter-and-som-decoder.html)

I am also working to improve the SOM decoder to handle the "outliers" - CW characters containing errors due to noise spikes or timing problems  -  see more details in the blog in here
http://ag1le.blogspot.com/2012/05/morse-code-decoding-with-self.html (http://ag1le.blogspot.com/2012/05/morse-code-decoding-with-self.html) .

73
Mauri AG1LE


Title: RE: FLDIGI: two new experimental features to improve CW detection and decoding
Post by: STAYVERTICAL on May 21, 2012, 03:47:35 PM
You guys are all geniuses (and I don't mean that in the discounted way it is used these days).

I would like to thank you, Dave and all the other FLdigi developers, for developing and progressing FLdigi.
Although my computer skills are not up to the task of doing something like that, I can appreciate art in programming when I see it.

73 and many thanks for this great software.
- Rob


Title: RE: FLDIGI: two new experimental features to improve CW detection and decoding
Post by: AG1LE on May 23, 2012, 08:24:43 PM

I would like to thank you, Dave and all the other FLdigi developers, for developing and progressing FLdigi.
Although my computer skills are not up to the task of doing something like that, I can appreciate art in programming when I see it.

73 and many thanks for this great software.
- Rob

Thanks Rob  :)

I think we really ought to thank  Dave & the team he has assembled around FLdigi.  I have learned a lot just studying the FLdigi software - it has some really cool collection of code. I have also found the team very responsive and helping  newbies like myself getting new ideas implemented.

Decoding Morse code is such a perfect application  area  -  there are enough challenges even for human operators to copy CW perfectly, not to mention teaching computers how to do it.  Add some noise,  irregular fists,  pile-up conditions, random signal fading and other daily events on the ham RF bands - creating smart software that is able to deal with all this and software that learns from experience is quite a challenge.  We have now personal computers powerful enough to run complex algorithms in milliseconds  that took hours when  these neural network algorithms were first discovered 20 - 30+ years ago.

I wonder if there is anybody else interested in Self Organizing Maps and other artificial neural networks algorithms?

73
Mauri  AG1LE





Title: RE: FLDIGI: two new experimental features to improve CW detection and decoding
Post by: AG1LE on May 28, 2012, 11:29:57 PM
Quote
I am also working to improve the SOM decoder to handle the "outliers" - CW characters containing errors due to noise spikes or timing problems  -  see more details in the blog in here
http://ag1le.blogspot.com/2012/05/morse-code-decoding-with-self.html (http://ag1le.blogspot.com/2012/05/morse-code-decoding-with-self.html) .


New test results in here: http://ag1le.blogspot.com/2012/05/fldigi-analysing-som-decoder-errors.html


73
Mauri AG1LE